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Discussion Starter · #1 ·
I may be in the unique position to review both the ISCO II and the Panamorph very soon. I'd love some ideas on what metrics I should use to compare the two. Some of the ideas I had are:


1. Using a checkerboard pattern and lightmeter measure the contrast ratio.

2. Using a Snell & Wilcox or a self-made pattern test for focus and maybe even contrast in each of the corners and center.

3. Maybe use a VA-1 to establish a baseline color temp then take a few readings for each unit to see if there is any change to color?

4. Maybe use the widescreen overscan pattern on AVIA to measure how close I can get to 16:9 or 75% compression?

5. Obviously, subjectively gauge the amount of set up time and ease of use.


Any other thoughts would be appreciated!


Tom
 

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1) Min and Max throw ratios.

2) Amount pincushion or barrel distortion.

3) Keystone distortion or best vertical position for projector relative to top or bottom of screen.


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Jim Nissen
 

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tommyboy2,


Please add thru-loss (efficiency percentage) to the list (adjusted for equivalent screen surface area)


Thumper
 

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Hi,


I am also very interested on the amount of optical distortion made by these two attachments. Maybe a projector with optical lens-shift would be ideal to discuss possible differences made through the projector-height vs. the screen.


Best regards, Walter


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Graz, home town of the Terminator...
 

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Discussion Starter · #5 ·
Quote:
Originally posted by Thumper:
tommyboy2,


Please add thru-loss (efficiency percentage) to the list (adjusted for equivalent screen surface area)


Thumper
You guys are hard core! OK Thumper...but how do I do that?


jnissen, do you want me just to verify the min/max throws? This may be tough since my D-ILA is ceiling mounted in a hushbox and my screen is an electric drop-down. I'll comment on the pincushion and just rank them and maybe toss in some photos if that helps.


Thanks guys! Good feedback so far.


Tom

 

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I could suggest a method for determining the relative light loss but it would require the use of a digital camera and a little physics.


If you have a digital camera on which you can control the shutter speed so that it's constant then you can set the camera to take a picture of the image after it is adjusted for equivalent area. Since the aspect ratio will be affected by the lens getting the projected image to occupy the same area will take a little bit of math, but it shouldn't be too hard to figure that out.


Now project a solid image that is a shade of white. Take a picture with the electronic shutter set to a constant exposure. Check to make sure the resulting image does not cause the image to be over exposed. Now without changing any settings on the camera change the lens and adjust the zoom setting. Take another exposure.


The idea here is that a CCD responds to light intensity in a linear manner up until it becomes saturated. Using the resulting images converted into a color space that can be read in RBG take the root mean square of the three color readings for a central area of the image. This can be used a measure of the intensity of the light. Do the same for each image using the same central area. Any difference in values is the result of absolute intensity. A more accurate estimate of the relative difference may be obtained by averaging the root mean square values for several pixels and using that for the measurement.
 

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Please also add light clipping percentages over zoom range.


Measurements of distortion by taking into account thermal efficiency over variable room temperatures.


Center to edge focus and lineraity over variable compression range.


Confirmation of the down wall ratio to throw distance (any irregularities).


Report any variations on the image when distance of anamorphic lens is close or far from projector lens

(I am concerned about clearance issues and sliding Panamorph)


Report variations of focus adjustments needed or not needed when by-passing the lens to use full 1:33 panel for 1:33 images.


Foot Lamberts change on 20,50 and 100 IRE windows both with and without the lens.


Report color shifts and tightness on small dot geometry.


DavidW
 

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Tommy,


Aren't you glad you asked?
 

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[\\start of bovine waste product]


I'm surpised no one has asked for a comparison of spectral efficiency as it relates to a 4th order tensor of surface brightness on a fully normalized per quantum basis.


I would think this would be a "must" for any serious and objective comparison.


[\\end of bovine waste product]



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Calibrated G11 DILA, 7' 16x9 Greyhawk, Radeon HTPC, Panamorph (soon), DTC-100, AccessDTV, Lexicon MC-1+, B&W Nautilus 804's, HTM1, SCM1s
 

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Tom,


My real interest is how much of the zoom range of my Dukane 9015 can I use with each lens. We are all going to appreciate your review.


Thanks,


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Jim Nissen
 

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Tommyboy2,


By "very soon" do you mean you will be receiving a production unit Panamorph in the near future? If so, can you share information about the arrival date? I ask because

the wait for the Panamorph is becoming interminable and I am not interested in reading a "teaser" report based upon a Panamorph prototype of testing model. If you are going to test a "power buy" unit that was shipped as part of the general release, that would, of course, be great.


Jim
 

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Mark Petersen,


You should be able to compensate for any differences in the spectral efficiency of the two lenses by shunting some variable fraction of warp power through the deflector dish.


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Kirk Ellis

G1000 D-ILA, HTPC, Panamorph (soon I hope),

Dish 6000 (HBOHD,SHOHD,CBS,NBC,ABC,WB,FOX,UPN, KCET -- does it get any better ?)
 

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Discussion Starter · #16 ·
Quote:
Originally posted by Tryg:
How about this measurement.



1. Does the product actually get delivered.
Now this one I can handle! I'll have my Panamorph on Saturday and will post my tracking number tomorrow if that helps.


Thanks for all of the great questions - boy, I'm am sooo glad I asked! http://www.avsforum.com/ubb/smile.gif


I think I may have to keep this review extremely subjective for fear any measurements would be shred to pieces within 5 minutes of being posted! So here is my final review categories:


1. The color of the lens (or at least the color my eye/brain thinks the color should be) and how nice it matches my decor


2. Does the lens fog up when I breath on it and can I write "clean me" on it with my finger? (bonus points if the "clean me" somehow shows up on my screen)


Tommy-the-optical-engineering-dyslexic-boy2 http://www.avsforum.com/ubb/smile.gif
 

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David,


If you run out of gas for your Ducane, you can use Dukane 9015 (JVC G15 equivalent) exhaust fan to cook your dinner.


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Jim Nissen
 

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Hey! I have a Ducane also. Damn fine grill....
 

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So do I, but I got my Dukane 9015 before my Ducane. My priorities are straight, HT before food!


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Jim Nissen
 

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How about this measurement.



1. Does the product actually get delivered.
 
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